Known roll type rolling machines and roll type correcting machines are classified into two types: the cantilever type in which the roll shafts are supported by a roll support frame installed on one side of the pass line, and the dual-support type in which the roll shafts are supported by two roll support frames installed on the opposite sides of the pass line.
In the cantilever type with roll shafts supported on one side, since the other side of the roll shafts are open, roll exchange is easy. However, in the cantilever type, a heavy load on the rolls would present a problem that the roll shafts deflect to make precision processing impossible. In the dual-support type with roll shafts supported at opposite sides, there is a problem that roll exchange takes much time.
In recent years, the number of types of workpieces has increased, and there are many workpieces in the form of steel shapes which are equal in shape but different in size, suited to variety type small quantity production. However, in the known art, since the stroke for adjusting the roll width is so short that the number of distance sleeves used between rolls has to be increased or decreased to adjust the roll distance for each type of workpieces or roll exchange has to be made, presenting a problem that much time is taken for change of workpiece type.